Trying to keep up with the football this afternoon showed up a little problem listening to RealPlayer streams on the Intel version of OS X.
Bottom line is that RealPlayer is not yet a universal binary. So although it runs fine stand alone it doesn't support being embedded in a universal binary.
i.e. because Safari and Firefox 22.214.171.124 are in universal format, they cannot embed plugins that are not.
So the options are :
a) Regress to a nont universal binary version of Firefox
b) Use RealPlayer as both a browser and player - i.e. when you want radion/video enter http://news.bbc.co.uk/ into RealPlayer and browse using it.
I've gone for b) - but I will investigate mplayer for time shifting shows.